Sexuality under the microscope in Showtime's 'Masters of Sex' series

BEVERLY HILLS, California (Reuters) - The sexual revolution has been well-documented on TV shows like HBO's "Sex and the City," but a new Showtime drama "Masters of Sex" turns the lens on the pioneering couple who started the public conversation about sexuality.

The show, which premieres on September 29, explores the early relationship of groundbreaking sex researchers Virginia Johnson and William Masters. It documents their discoveries based on Thomas Maier's 2009 biography "Masters of Sex."

Johnson, who died last week at age 88, met Masters when she was a researcher for him at Washington University in St. Louis in the 1950s. Masters, who died in 2001, was a physician at the university and had begun researching sex in 1954.

British actor Michael Sheen, who plays Masters, said he was drawn to both the complexity of his character and the subject matter of researching sexual behavior at a time when talk of sex publicly was considered taboo.

"(Masters) is sort of a mystery to himself. He has so many locked rooms inside himself and he has to tread very carefully to make sure he controls his environment," Sheen said at a Television Critics Association meeting in Beverly Hills on Tuesday.

The show features many explicit scenes of sex, both in and out of medical settings, but Sheen said it explores topics far beyond just sexual gratification, and also resonates with the issues around the subject today.

"It doesn't matter if we know a lot more about sex or have more access to it now. It's the same problems with intimacy and dealing with people, of connecting and being vulnerable with other people, which is ultimately what the show is all about," the actor said.

Masters and Johnson, who married in 1971 and divorced after 20 years, were best known for their 1966 book "Human Sexual Response," written after years of testing of sexual arousal in couples. They published a second study, "Human Sexual Inadequacy," in 1970 and often appeared on talk shows and other programs to discuss their research even after their divorce.

"Masters of Sex" creator Michelle Ashford said she was eager to explore the couple's own relationship.

"Their story just needed to be told. No one really knew what they did, but they were instrumental in the historical movement of not only how we viewed sex but how we viewed men, women and society," Ashford said.

Sheen added that having the show on cable network Showtime allowed them to explore the topic of sex with more freedom than on conventional broadcast television channels, which are regulated by federal rules restricting nudity and graphic content.

On cable, "any subject matter is open to you, you can take risks and you've got 12 hours roughly per season to go into it ... you can start to treat characters with the complexity that they deserve," he said.